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RAG · Agentic AI2026

RegelWerk

RAG that refuses to answer without a verified legal citation.

RegelWerk — RAG that refuses to answer without a verified legal citation.

The real app, running live — interact with it right here.

The problem

Most RAG demos stop at retrieval and happily hallucinate citations. For a legal-rules assistant, an unbacked claim is worse than no answer.

The solution

A Swiss tenancy-law Q&A where every statement traces back to a cited article. A second, adversarial agent verifies each citation against the real article text; unbacked claims are flagged and the answer is revised. No source, no answer.

What it does

  • Citation verification by a second adversarial agent
  • Guardrail rejects off-topic questions instead of hallucinating
  • 116 legal articles embedded in Supabase pgvector (HNSW, cosine)
  • Tool calling with zod-validated schemas (searchLaw, getArticle)
  • Eval: 20/20 retrieval hit-rate over a fixed question set

How it works

  1. 1

    Retrieve

    The question is embedded with Gemini and matched against 116 articles in pgvector; a score threshold guards against off-topic queries.

  2. 2

    Answer with tools

    An answer agent composes a response using searchLaw / getArticle tool calls, quoting specific articles.

  3. 3

    Verify & revise

    An adversarial checker validates every [Art. XXX] reference against the real text and forces a revision if any claim is unbacked.

Architecture

Click a node to see what it does.

Tech stack

  • Next.js
  • TypeScript
  • Gemini
  • Supabase pgvector
  • Zod